BIT-dotnet-2021-26423 — .NET Core and Visual Studio Denial of Service Vulnerability

Affected: Bitnami: dotnet

.NET Core and Visual Studio Denial of Service Vulnerability

certfr-2021-avi-619 — De multiples vulnérabilités ont été corrigées dans Microsoft .Net. Elles permettent à un at…

certfr-2021-avi-619

EUVD-2026-349776

fkie_cve-2021-26423

.NET Core and Visual Studio Denial of Service Vulnerability

GHSA-rh58-r7jh-xhx3 — .NET Core Elevation of Privilege Vulnerability

Affected: NuGet: Microsoft.NETCore.App.Runtime.win-x86, NuGet: Microsoft.NETCore.App.Runtime.win-x64, NuGet: Microsoft.NETCore.App.Runtime.win-arm64, NuGet: Microsoft.NETCore.App.Runtime.win-arm, NuGet: Microsoft.NETCore.App.Runtime.osx-x64, NuGet: Microsoft.NETCore.App.Runtime.Mono.osx-x64, NuGet: Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64, NuGet: Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64, NuGet: Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64, NuGet: Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64 and 13 more

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 5.0 and .NET Core 3.1. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A denial of service vulnerability exists in .NET 5.0, .NET Core 3.1 and .NET Core 2.1 where .NET (Core) server applications providing WebSocket endpoints could be tricked into endlessly looping while trying to read a single WebSocket frame.

### Patches

* If you're using .NET 5.0, you should download and install Runtime 5.0.9 or SDK 5.0.206 (for Visual Studio 2019 v16.8) or SDK 5.0.303 (for Visual Studio 2019 V16.10) from https://dotnet.microsoft.com/download/dotnet-core/5.0.

* If you're using .NET Core 3.1, you should download and install Runtime 3.1.18 or SDK 3.1.118 (for Visual Studio 2019 v16.4) or 3.1.412 (for Visual Studio 2019 v16.7 or later) from https://dotnet.microsoft.com/download/dotnet-core/3.1.

* If you're using .NET Core 2.1, you should download and install Runtime 2.1.29 or SDK 2.1.525 (for Visual Studio 2019 v15.9) or 2.1.817 from https://dotnet.microsoft.com/download/dotnet-core/2.1.

#### Other Details

- Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/194 - An Issue for this can be found at https://github.com/dotnet/runtime/issues/57175 - MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-26423

msrc_CVE-2021-26423 — .NET Core and Visual Studio Denial of Service Vulnerability

msrc_CVE-2021-26423

RHSA-2021:3142 — Red Hat Security Advisory: .NET Core 3.1 security and bugfix update

dotnet: ASP.NET Core WebSocket frame processing DoS dotnet: Dump file created world-readable dotnet: ASP.NET Core JWT token logging

RHSA-2021:3143 — Red Hat Security Advisory: .NET Core 3.1 on RHEL 7 security and bugfix update